L-Carnosine
β-alanyl-L-histidine · C9H14N4O3 · monoisotopic 226.1066 Da. The index holds 26 assay reports on this compound across 6 batches from 6 suppliers.
Analytical fingerprint
Hand-authored chemistry. These properties describe the substance and do not change when a record is added.
Carnosine is a dipeptide sold in gram quantities and the index tracks it mainly as a contrast case: at 3.72 min on C18 the compound is barely retained and the appropriate method is HILIC or ion-pair chromatography with a copper-complexation or OPA-derivatisation detection scheme. Anserine at +14 Da is the diagnostic natural-source contaminant and its presence indicates animal-tissue extraction rather than synthesis, which is a provenance finding the index reports on the batch page.
- Compound class
- Short bioregulator peptides
- Molecular formula
- C9H14N4O3
- Monoisotopic mass
- 226.1066Da
- Average mass
- 226.23Da
- Residues
- 2
- Nominal retention (RG-2, 30 min)
- 3.72min
- Retention window
- 0.20min
- Counter-ion as usually shipped
- none expected
- Typical label claims
- 500 mg · 1000 mg
- Analytical difficulty (index scale)
- 0.85 — straightforward
- Purity is a defined quantity
- YES
Representative chromatogram
Drawn from this page's own medians. Not a scan, not an illustration, and not any single report.
What the index has observed
Arithmetic over the 26 records the index holds. Aggregates on this page are computed over the records the index holds, which are not a random sample of the material on the market. Lots that get tested are lots someone chose to test. Read every figure here as a description of this dataset rather than as an estimate of a population.
By supplier
Suppliers with fewer than two purity records on this compound are omitted from the figure rather than drawn as a line. The full table, including the thin cells, is on the by-supplier page.
Characteristic impurities and degradants
The left three columns are authored chemistry — what this molecule characteristically carries and where it elutes. The right three are what the index has actually reported.
| Named species | ΔRT (min, RG-2) | Δ mass (Da) | Seen in | Median % area | Max % area |
|---|---|---|---|---|---|
| D-carnosine epimer | -0.06 | mass-identical | 96% | 0.14 | 0.75 |
| free histidine (−71 Da) | -0.16 | -71.037 | 92% | 0.07 | 0.68 |
| β-alanine (−137 Da) | -0.22 | -137.059 | 85% | 0.08 | 0.40 |
| anserine (methylcarnosine, +14 Da) | +0.12 | +14.016 | 81% | 0.10 | 0.40 |
Degradation pathways
- hydrolysis by residual carnosinase activity in impure aqueous media
- racemisation under heat
Full impurity profile, with what each named species implies about the synthesis →